氢燃料电池汽车不同制氢方案的全生命周期评价及情景模拟研究

氢燃料电池汽车作为新能源汽车领域未来的重要方向已成为行业共识,为评估氢燃料电池汽车不同制氢方案对资源、能源和环境的影响,构建氢燃料电池汽车燃料循环以及4种制氢方案的全生命周期评价数学模型,选取代表世界先进水平的丰田Mirai燃料电池汽车作为评价对象,应用GaBi软件的基础数据库对其进行全生命周期评价,同时对甲烷催化重整法、甲醇催化裂解法、电解水法和氨裂解法4种制氢方案的全生命周期能耗、排放进行量化计算。最后,以电力结构作为关键因素对当前最常用的电解水法进行情景模拟并与其他3种方案进行对比分析。评价计算结果表明:电解水法制氢的矿产资源消耗、化石能源消耗和环境影响均最高;甲醇催化裂解法制氢的矿产资源消耗和化石能源消耗均为最低,仅分别为电解水法的2%和3%;甲烷催化重整法制氢的环境影响最低,仅为电解水法的1.6%。情景模拟结果表明:电解水法的环境影响在煤电比例降低到41.6%的情况下仍然在4种制氢方案中最大,然而在水力单一清洁能源发电的极限情况下环境影响最小,但基于中国的资源禀赋,全面实现水力发电并不可行。因此,须从提升电解水法的能源利用效率、改进关键技术等方面有所突破才能使其成为未来大规模制氢的可行方案。

Life-cycle Assessment and Scenario Simulation of Four Hydrogen Production Schemes for Hydrogen Fuel Cell Vehicles

The current industrial consensus is that the development of hydrogen fuel cell vehicles will be an important direction in the future of new-energy vehicles. Therefore, the impact of four hydrogen production schemes for hydrogen fuel cell vehicles with regard to the resources, energy, and environment was evaluated in this study. For this, a mathematical model was established to evaluate the fuel cycle of hydrogen fuel cell vehicles and the life cycle of the four schemes. Toyota Mirai, which currently represents the most advanced level of hydrogen fuel cell vehicles, was considered as the evaluation object, and the basic database of Gabi software was utilized to evaluate its life cycle. Simultaneously, the life cycle energy consumption and emissions of the following four hydrogen production schemes were quantitatively calculated: catalytic reforming of methane, catalytic cracking of methanol, water electrolysis, and ammonia cracking. Finally, considering the power structure as the key factor, a scenario simulation was conducted on the water electrolysis scheme, and it was compared with the other three schemes. The evaluation results show that the water electrolysis scheme has the greatest influence on mineral resource consumption, fossil energy consumption, and environmental impact. Catalytic cracking of methanol has the lowest mineral resource and fossil energy consumptions, which are only 2% and 3% those of the electrolytic water method, respectively. The environmental impact of methane catalytic reforming is the lowest, which is only 1.6% that of the electrolysis scheme. Scenario simulation results show that the water electrolysis scheme has the most significant environmental impact among the four hydrogen production schemes when the coal-electricity ratio is reduced to 41.6%. However, the environmental impact is minimal under the condition of single clean energy generation. Based on China’s resource endowment, it is impossible to realize hydroelectric power generation in an all-round manner. Therefore, breakthroughs to improve the energy efficiency and to develop key technologies for water electrolysis are necessary to transform it into a feasible scheme for large-scale hydrogen production in the future.